Laid-open German Application No. 15 78 648 discloses a training implement for a physical exercise which is similar to weight lifting. That implement comprises a rope, which is braked by a friction brake and can be pulled out of a mounting frame. The braking force exerted on the rope can be adjusted with reference to a scale but the tensile force which is actually exerted cannot be exactly determined.
Laid-open German Application No. 14 78 056 discloses a muscle-training implement having one member which is to be moved by hand along a path that is defined by a rail track. The velocity at which that member can be moved is adjustable with reference to a scale. A motor drive is provided, which acts on said member, which is thus subjected to the muscle force that is exerted and the force exerted by the motor. Means are provided for indicating the difference between the total force acting on the member and the measurable motor force. The implement for heavy exercise cannot be used in competition.
Implements for muscle training have been provided, particularly for training the hand and arm muscles. These implements comprise a torsion spring, which has two end legs that extend out of a housing and must be removed toward each other. One leg of the torsion spring is secured to the housing. The other leg constitutes a pointer, which is movable along a scale provided on the housing so that a coarse indication is provided of the force which is exerted on the two spring legs to force them toward each other. An objective measurement of force and an exact determination of the maximum force that has been exerted are not possible.
As has been mentioned above, all known implements of the present kind for heavy athletics are mainly intended for training and can only approximate the exertion of force and motion required in a single actual sport. In the abovementioned implement for weight-lifting training, the force to be overcome is constant and the extent to wich the rope is to be extended depends on the size of the body of the user. In the other implements the force that has been exerted is indicated by the extent to which a member has been moved or by the velocity at which it has been moved. A simulation of any exercise of heavy athletics requires a specific implement, which is designed for that exercise and provided with a separate measuring instrument and with the exception of the lift-training implement most of said measuring instruments depend on displacement and are not sufficiently exact.